Virtual Field Reference Data Base

The Landscape Characterization Branch within the Office of Research and
Development has developed the Neuse River Basin "Virtual Field Reference
Data Base (VFRDB)" for the purpose of providing in situ reference
measurement data for statistically rigorous accuracy assessments of land-cover
maps derived from satellite and airborne remote sensing platforms.
Vegetative and physiographic components were measured on 1,409 plots
(0.42 hectares) over a two-year period (1998-1999) using stringent quality
assurance protocols to ensure statistical reliability and repeatability.
The "virtual" component of the database is the high resolution (1,040
x 840 pixels) natural color imagery series that were acquired for each site.
The U.S. Environmental Protection Agency's Office of Research and
Development is making these data available to all interested parties via
this website.

The Neuse River Basin (NRB) is contained entirely within the state boundaries
of the state of North Carolina. The basin boundaries were delineated
based on the U.S Geological Survey (USGS), 6-digit hydrologic unit code (030202).
The NRB is 14,582 km2 in area and contains 16,900 km
(1:24,000-scale) of stream length. The upper (northwestern) third of
the basin is located in the piedmont physiographic region and the remainder
in the mid-Atlantic coastal plain. Elevations within the NRB range
from 276 meters in the western part of the basin to sea level at the confluence
of the Neuse River to Pamlico Sound. The confluence represents the southern
extent of the Albemarle-Pamlico Sound estuary system which is defined by
a series of barrier islands called the North
Carolina's Outer Banks.